Method of and apparatus for administering repeated injections



Nov. 28, 1950 B. J. BRENT 2,531,667

METHOD OF AND APPARATUS FOR ADMINISTERING REPEATED INJECTIONS Filed Dec. 1, 1947 Z7 Z3 INVENTOR.

Patented Nov. 28, 1950 METHOD OF AND APPARATUS FOR, ADMIN ISTERIN G=REPEATED INJECTIGNS- Bernard J Brent, Montclai1-:,N.,J.

Application December 1, 1947, Serial No. 789,088-

1.00laims.

This invention, relates to. method of: and; apparatus for administering repeated injections;

and it comprises a syringe, adapted to. be:

strapped to the leg: or: arm of a patient, for example, provided with a flexible discharge tube adapted to? dwell. in: a. patient. during the period of treatment; said syringe comprising in combination a barrel having an. open end and a closed end, an upstanding; plungermounted centrally in said: barrel and extending from said closed end toza point abouthalfrway to the-open end of said baimel', an injection needle mounted longitudinallyrin and extending. throughsaid plunger and:

passing'through the closed end of said. barrel, said needlahavingg a; sharpened inlet and extend ingr a. short distance beyond said plunger and a discharge end,.a;.flexiblesinjection tube having an inlet end securedyto the discharge end of. said needle and a discharge: end adapted. to be insented ina pati'enha tubular ampoule containing an injectionvfluid having a sliding fit inside said barrel and adapted to receive. and to slide oversaid plunger during an injection, said am-poule having a discharge end and av closedend, a resilient plug normally closing; said discharge end, and means: forthrusting said ampoule into: said: barrel; said plunger; ampoule, needle and. barrel being. so constructedandarranged that when said. ampouleis inserted in said barrel and thrust home the inlet. end; of said needle punctures said plug, thereby establishing communication between the interior of said needle-and: the: interior of said. ampoule and said plunger presses said plug through the body of the ampoule causing the. liquid in" the ampoule to be discharged through said needle and through said flexible tube into the patient. cludes a method of administering repeated injections by means of said syringe which comprises inserting the: dischargeend of the flexible tube. ot the syringe into a; patient, securing the barrel of the syringe to a patient in such mam net that the tube end will not he accidentally withdrawn, inserting the sterilized plugged end of, said? ampoulein. said barrel, pressing the ampcule' home thereby discharging the: injection.

The invention also in-- membrane.

Modern therapeutics frequently requires a plurality of intravenous or other injections to be made at frequent? intervals and over periods which: may extend for several days or weeks. Owing to'the acute shortage of skilled medical: attendants, cases of this type have presented at difiicult problem tothe: medical profession. Severali different injection techniques have been developed for this purpose making use of an injec- 1 tion needle inserted ina vein and left in situ over the period during which repeated injections are required. In one method a rubber membrane has been attached at, the end of the needle and inject-ions have then been made through this In others rubber tubes or needles have been left inserted. in a vein and various devices have been developedto enable syringes tobe attached, discharged into the vein and then. removed without contamination. None of these devices has proved to be entirely successful, some causing injury to the vein and some being subject to" contamination While all have required at least semi-skilled attendants to operate them.

I have discovered what appears to represent an ideal solution to the problem outlined above in that I havediscovered a method which eliminates the necessity for skilled attendants to administer the injections and have therefore made it possible for the patient to become amloulatoryv and even to engage in normal routine work during the period of treatment. My new injectiondevicemakes use of a syringe which is usually attached to the leg of the patient and provided with a flexible tube inserted and left to dwell in the patient during the period: of treatment. The syringe makes use; of replaceable injection ampoules closed with. resilient plugs which serve as pistons during the injection operation and in which thesyringe needleis adapted. to pierce the p ugs toestablish communication between the interior of theampoules and the interior of the needle, the discharge end of the needle being attachedto a flexible tube which is inserted in the patient. With this type of syringe the only oints which must be sterilized during, a series of in jections are the resilient plugs at the ends of the am-poules since these are the only points contacted, by the injection fluid, this contact being made as the needle pierces the plug duringthe injection. In one embodiment of my invention the plasticv plugs are sterilized when the arnpoules are made and covered by a removable, sterile cap. With this device it is on y necessary to remove the capsfrorn the ends! of the ampoules before: making injections, no separate sterilization Figs. 2 and 3.

of the plug being required. But even in the absence of the sterile cap it is a simple matter for the atient to flame the plastic plugs at the ends of the ampoules or to wipe them with a disinfecting solution before inserting the ampoules into the syringe barrel. It is an equally simple matter to press an ampoule into the barrel thus making an injection. The ampoule is left in thrust home position between injections and thus prevents contamination during these periods. The method is more or less fool-proof in that the danger of admitting air into the injection fluid is practically eliminated.

My injection method is applicable in the case of any treatment requiring the repeated injection of therapeutic fluids. It is particularly adapted to intravenous injections but can be applied to intraperitoneal, subcutaneous and other injections as well. Heparin, insulin, cortical extract, desoxicorticosterone and penicillin, for example, can be advantageously administered by this method.

A specific example of an injection fluid which can be administered advantageously by my method is an isotonic solution of sodium heparin containing 50 mg. of sodium heparin per cc. It is possible to inject this heparin fluid intravenously by my method at the rate of 1 to 1.5 cc. at 4 hour intervals with an injection of 2 to 2.5 cc. before retiring, for example, in cases where such treatment is indicated.

My invention can be explained with more particularity by reference to the accompanying drawing which shows more or less diagrammatically several embodiments of my injection syringe and a method of mounting the same on the leg of a patient. In this showing Fig. 1 is an elevational view of the leg of a patient with one of my inj ection syringes mounted thereon,

V Fig, '2 is an elevation, drawn approximately to scale, of my injection syringe with its ampoule plunger ready to be inserted, while Fig. 3 is a longitudinal sectional view on an enlarged scale of the syringe with plunger fully inserted, as at the end of an injection,

Fig. 4 is a longitudinal section through the discharge tip of the injection needle, on an enlarged scale, showing means for adapting the needle to receive and hold a flexible injection tube,

Fig. 5 is a partial longitudinal sectional View through the lower end of a modified form of syringe, while Fig. 6 is a side elevation of one end of a modified ampoule to be used in my syringe.

In the various views like parts are designated by like reference numerals. Referring first to Fig. 1, the syringe, shown generally at l, is strapped to the patients leg 2, by bands 3 of adhesive tape or the like. The flexible injection tube or cannula ti, usually made of synthetic rubber, nylon or other flexible material, has its discharge end 5 inserted in a vein and it remains in this position during the treatment. In Fig, 1 the ampoule tube, shown generally at 6, is in its thrust-home position, as at the end of an injection, and it remains in this position in order to .prevent contamination until time for another injection.

The details of the syringe are shown best in The barrel orcylinder I of the syringe is preferably made of an artificial plastic, such as a transparent vinyl polymer resin. At its open outer end it is provided with the conventional finger grip "8. At its closed inner end an upstanding integral plunger 9 is provided which is sealed to the base it of the cylinder. A central needle H is provided which passes through the base and is supported by a bead l2 of plastic. The outer end 93 of the needle extends beyond the outer end of the plunger 9 for a purpose which will become clear from the following description.

The discharge end M of the needle extends outwardly beyond the plastic bead for a sufficient distance to enable the injection tube 4 to be secured thereto. This end is adapted to receive and hold the flexible injection tube, as shown best in Fig. 4. The discharge tip of the needle is advantageously beveled, as at IS, in order to prevent the injection tube from being cut when slipped over this tip and it is usually desirable to provide means close to the tip serving to hold the tube so that it will not become accidentally removed, such as the bead It. If the end of the needle is knurled for a short distance this also tends to prevent accidental removal of the tube.

In Fig. 5 a modified syringe is shown which is provided with a special means for holding the flexible injection tube on the needle oi the syringe. This syringe is constructed of metal and at its lower end it is provided with a short threaded extension 820. which is bored to receive the needle lid. The needle can be soldered or otherwise secured in the bore of the extension. The needle is tapered as at 24 to receive the flexible injection. tube i and a retaining nut 25 is provided with a corresponding internal taper at 26. The nut is internally threaded so it can be screwed on the extension [2a. After the flexible tube isslipped over the end of the needle and at least part way over the tapered section of the needleythe re taining nut can then be applied to the extension and, when tightened, its internal taper presses against the end of the flexible tube so as to hold it tightly i position and to prevent accidental removal.

The particular ampoule tube 5 which is shown. in Figs. 2 and 3 is divided into two injection fluid holding ampoules i! and i8 by means of a central partition i9, these ampoules being closed at their outer ends by resilient plugs 20 and 2!, usually made of rubber. The ampoule tube is usually constructed of glass although a plastic can be used if desired. At its top a removable resilient cap 22, usually made of rubber, is provided to provide a thumb rest during an injection. The cap has a socket which fits over the end of the tube as shown. The ampoule tube is reversible and, after one ampoule has been used, the can can be placed over the end of the empty ampoule and the second ampoule is then ready to be used.

In Fig. 6 one end of a modified ampoule is shown. This ampoule is closed at its end by a can be applied by shrinking thecap over the end or the ampoule after sterilization or by dipping the sterilized end of the ampoule in a sterile solution of the plastic material. Removal of the cap exposes the rubber plug which requires no further sterilization before being inserted in the syringe.

It is possibl to employ a closely fitting rubber cap. in: the form; of: asock et. fitting. over the; n

ofitheiampoule, which; can; be removedgby, merely pulling it off. The use of a tear strip isprefer ablozhowever, since it is impossibleto-remove this typeof. can without destroying: it.- This. prevents tampering.

In: order toinject. thefluid from: one of: the ampoules; the: tube; 5,. after sterilization. or its plugged.- end, if. nec essary; inserted-into.- the-bar.- rel- 1:50 thatithe end l3: of. the needle l l. presses against. the resilient plug 20.. lane-tube isthen thrust; homein usual manner during which one oration the needle punctures the resilient. plug. in; the ampoule, after'which the plunger 9., which: fits insidethe ampoule, serves to push the plug. tot-the: rear of the. ampoule. Theplug thus. acts: as a pistonlto force theinjectionfiuidout oi. the ampoulethrough the needleand thuswutthmugh. the flexible tube; 4. lihe injection fluid. which. is iniected comes in contact onlywith the ti -and: the. inside of the needle and the inside of. the flexibletube during. the injection.

'Iihe-am-poule. tube is. leftin thrust-home posir tion until= time for the. second injection. At this time; it: is withdrawn, the cap. 22.. is. removed; and. placed. over-the endof the empty ampoule, the tube. is'then reversed, the end of the plug; 2!.- is. sterilized; .if necessary, and thenthe tube. is-readyl to beinserted in the cylinder for the secondginjection.

Whenmy device is; first applied: to a patient. the. fiexiblertubeisinserted in a vein, for example, by: means of a trocar. having lumen. slightly larger than the flexible tube. The trocar. is. first inserted in. the: vein. andthe flexible tube. is slid; through. the trocar into. its desired position. in the. vein and-the trocar isthen. removed by sliding it backwardly over the flexible tube While holding. the. outer end-of the tube toprevent itsremoval from the. vein. The flexible tube. can thenv be; shortened, if desired, by cutting it with scissors... It is desirable at this point to. securetheflexible. tube. tothe body of. the patient by placing an.ad. hesive-tape over the tube, close to the wound} in. order to prevent accidental. removal. The. free end of the. flexible tube is. then attached: to the discharge end. of. the syringe, for. example by slip.- ping its; endover. thesyri-nge needle. Thesyringe. shouldthen be secured. to. the-body of the patient by adhesive tape- Before making. thefirst injec tion the flexible tube and. syringe needle. should; be-iree :E-rom air. Owing. to the capillary. effect. of theflexible tubeand thesyringe. needle aswell. as the: venus pressure the. tube and-needle will usually fill with blood. without. assistance. If. necessary, however, a slight. suction can. be applied. to the open end. of. the syringe barrel to accomplish this result. When this has beenac.- compl-is-hedthe device is ready for the first -injec tion. as described. previously.

It should. be noted that there is, little or. no danger 0t introducing air into. theneedlebetween. or during. injections when use is made. of. the device described. Whenthe. ampoule tube is with.- drawn. from. the. syringe cylinder only a slight suction is produced as. theneedle passes through the resilient plugand, of. course, .asthe end. of the needle leaves. the. plug. the needle is. full of fluid. and remains so during. the interval. between. with.- drawal of the aznpoule. tube. and re.-insertion.. Due to. the veinouspressure theneedl remains. filled or it may even bleed slightly at. its. end 1.3 which can be. stopped by pressure. exerted. upon. the. flexible tube. The. ampoulesv are. advantageously air free. Otherwise they are. filled. to. a.

suflicient-extent so that no air can. enter they in? jeotionl needle during; an injection... The; danger.

off air embolism is thus completelyzavoided.

While I havedescribed what. I. consider. to, be themost advantageous embodiment of. myvprocess: it. is. evident, of: course, that variousmodifieations:

can bemade in the; specific procedures andstruc tures whiclr have i been described without;- depart-. ingi from-lthe: purview of. this invention. As. in-= dicated previously my; method;- is, indicatedv when? ever: repeated injections.- particularly intravenous injections; are. required; And it. can be used to.

administer.- any of" the" conventional injection:- fluids. Ilhe*structure. of. my syringe. can; also-be varied considerably from; that which has been specifically described. Thus, it is. obviously pos- Sible; to employ single-- rather than. double-ended.

ampoules holding injection; fluid. The relative dimensions of the; various, parts. of the; syringe can: be varied. considerably and. the; syringe can be: constructed of any suitable; material, such as:

glass metal. or plastic.. The upstanding plunger- Wl'liCha surrounds: theneedle in. my syringe can; be: made either solid or tubular. The barrel of the:

- syringe-can lee-made of. non-circular cross-sectionifdesired. If.- made. of.- opadueimaterialit. canbe cutaway on. one: or both sides; to; provide observationwindows. In. some caseswherea long period. of medication is indicated, itisrdeSira-ble to providea cover for: my device to protect it, from being hit onpushedrout-of. place inadvertently; It. is. also possible to; use flexible tubes made: ofinylon', synthetic rubber or any of the modern. plastic elastomers provided that they are completely inert. Various ways. of attaching my; flexible. injection. tube to the discharge 811d; of the syringe: will occur to: those. skilled in the: art; And. any of. these can: be employed without; departing; from the present; invention. Further modifications: o my process and apparatus which fall withinthe scope or the. following. claims will; be immediately evident to those-skilled in. the art.

What: I- claim is l. A device for administering repeated. injec.- tions of, therapeutic fluids which comprises in combination an injection syringe having a barrel which: is open at one endand provided with adischarge opening at theother end, saidbarrel be.- ing, adapted to be secured to the; body of the pa tient during the period of treatment, a replace able ampoulecontaining an injection fluid adapt ed; to slide into the open end of said. barret, said ampoule: having a discharge end, normally closed by a, resilient; plug, a hollow needle mounted lon gitudinallyin said barrel, with an end adapted topierce saidresilient plug to establish communication between the injection fluid. in the: ampou le and the interiorof said needle when said am poule is pressed intosaid barrel; plunger means mount-- 1 edin saidbarrel adapted to push said plug as; a

piston into said asrnpoule to discharge said fluid into said needle as the ampoule is pressed into. said barrel, and a flexible tube havingan inlet end communicating with the. discharge opening of said syringe and a discharge end adapted to;

dwell. inthe patient during. the period of treat-- a barrel having an open end and a closed end, an upstanding plunger mounted longitudinally in said barrel and extending from said closed end to a point about half-way to the open end of said barrel, an injection needle mounted longitudinally in and extending through said plunger and passing through the closed end of said barrel, said needle having a sharpened inlet end extending a short distance beyond said plunger and a discharge end, the inlet end of said flexible tube being removably secured to the discharge end of said needle, a tubular ampoule containing an injection fluid having a sliding fit inside said barrel and sliding over said plunger during an injection, said ampoule having a discharge end normally closed with a resilient plug serving as a piston to expel the injection fluid through said needle during an injection; said plunger, ampoule, needle and syringe barrel being so constructed and arranged that when said ampoule is inserted in said barrel and thrust home the sharpened inlet end of said needle punctures said resilient plug thereby establishing communication between the interior of said needle and the interior of said ampoule and said plunger presses said plug through the body of the ampoule causing the liquid in the ampoule to be discharged through said needle and through said flexible tube into the'vein of a patient.

3. The device of claim 2 wherein a tubular double ampoule is employed with a partition in the center and having a resilient plug at each end holding two bodies'of injection fluid.

4. The device of claim 3 wherein a cap is provided to fit over the end of said ampoule and to serve as a thumb rest during the injection.

5. The device of claim 2 wherein means are provided for preventing said flexible tube from being accidentally removed from the end of said injection needle.

6. The device of claim 2 wherein the discharge end of said needle is beveled and provided with a bead to prevent the flexible tube from being accidentally removed.

7. In the administration of repeated injections of therapeutic fluids making use of a syringe having an open-ended barrel having a hollow needle mounted' longitudinally therein having a discharge end and a sharp inlet end, a flexible injection tube communicating with the discharge end of said needle, a replaceable ampoule containing an injection fluid having one end closed with a resilient plug capable of being forced into said ampoule as a piston to discharge liquid therefrom, the sharp end of said needle being adapted to pierce said plug to establish communication between the interior of said needle and the interior of said ampoule during an injection and a plunger in said barrel adapted to thrust said plug into said ampoule during an injection; the process which comprises inserting the discharge end of said flexible tube into a patient, establishing communication between the inlet end of said flexible tube and the discharge, end of said needle, mounting the barrelof the syringe on the patient, removing air from said tube and needle, inserting the sterilized end of an ampoule into the open 8 injecting its fluid into the patient and continuing the described procedure during the period of treatment.

8. In the administration of repeated injections of therapeutic fluids making use of a syringe have ing a barrel open at one end and with a discharge opening at the other end with a hollow needle mounted longitudinally therein having a sharp inlet end, a flexible injection tube communicating with the discharge opening of said barrel, a replaceable ampoule containing an injection fluid having one end closed with a resilient plug capable of being forced into said ampoule as a piston to trocar, establishing communication between the free end of the tube and the discharge opening of said barrel, securing the syringe to the patient in a position such that accidental withdrawal of said flexible tube from the body is prevented, eliminating air from said injection tube and needle, inserting the sterilized end of an ampoule into the open end of said barrel, thrusting home said ampoule thereby injecting its fluid into the patient, leaving the empty ampoule in position until time for a second injection, withdrawing the empty ampoule irom the syringe barrel, inserting the sterilized end of a second ampoule into said barrel, thrusting it home thereby injecting its fluid into the patient and continuing the described procedure during the period of treatment.

9. A syringe for administering repeated injections of therapeutic fluids which comprises a barrel provided with a threaded extension at one end and at the other end being adapted to receive an ampoule during an injection, a hollow needle secured in said threaded extension mounted longitudinally in said barrel, having a sharp inlet end adapted to establish communication between the interior Ofthe ampoule and the needle and a discharge end passing through said threaded extension, said needle being provided with a tapered section adjacent said threaded extension, a flexible injection tube adapted to be slipped over the discharge end of said needle'and over said tapered section, and an internally threaded retaining nut having an internal taper corresponding to the taper on said needle adapted to be slipped over said flexible tube and to secure said flexible tube on said taper when tightened on said threaded extension. 7

10. A device for administering repeated injections of therapeutic fluids which comprises in combination an injection syringe having a barrel which is open at one end and provided with a discharge opening at the other end, means for securing said barrel to the body of a patient, a replaceable ampoule containing an injection fluid adapted to slide into the open end of said barrel, said ampoule having a discharge end normally closed by a resilient plug, a hollow needle mounted longitudinally in said barrel with an end adapted to pierce said resilient plug to establish communication between the injection fluid in the ampoule and the discharge opening of said barrel when said ampoule is pressed into said barrel, means mounted in said barrel adapted to push said plug into said ampoule as said ampoule is pressed into REFERENCES CITED The following references are of record in the file of this patent:

Number Re. 16,836 785,524 1,798,142 1,848,711 1,961,023 2,153,594 2,313,483 2,354,649

a 10 UNITED STATES PATENTS Name Date Cook Dec. 27, 1927 Shea Mar. 21, 1905 Cressler Mar. 31, 1931 Hall Mar, 8, 1932 West May 29, 1934 Saifir Apr. 11, 1939 Smith Mar. 9, 1943 Bruckner Aug. 1, 1944 

